Log message if qss file can not be opened for write

src/blackgui/components/settingsfontcomponent.cpp

@@ -93,6 +93,7 @@ namespace BlackGui
 
         void CSettingsFontComponent::changeFont()
         {
+            if (!sGui || sGui->isShuttingDown()) { return; }
             const QString fontSize = ui->cb_SettingsGuiFontSize->currentText().append("pt");
             const QString fontFamily = ui->cb_SettingsGuiFont->currentFont().family();
             const QString fontStyleCombined = ui->cb_SettingsGuiFontStyle->currentText();

src/blackgui/stylesheetutility.cpp

@@ -9,6 +9,7 @@
 #include "blackconfig/buildconfig.h"
 #include "blackgui/stylesheetutility.h"
 #include "blackmisc/fileutils.h"
+#include "blackmisc/logmessage.h"
 #include "blackmisc/directoryutils.h"
 #include "blackmisc/restricted.h"
 
@@ -41,6 +42,12 @@ namespace BlackGui
         connect(&m_fileWatcher, &QFileSystemWatcher::fileChanged, this, &CStyleSheetUtility::qssDirectoryChanged);
     }
 
+    const CLogCategoryList &CStyleSheetUtility::getLogCategories()
+    {
+        static const CLogCategoryList cats { CLogCategory::guiComponent() };
+        return cats;
+    }
+
     const QString &CStyleSheetUtility::fontStyleAsString(const QFont &font)
     {
         static const QString n("normal");
@@ -247,11 +254,9 @@ namespace BlackGui
 
     bool CStyleSheetUtility::updateFont(const QString &qss)
     {
-        QString qssWidget("QWidget {\n");
-        qssWidget.append(qss);
-        qssWidget.append("}\n");
-
-        QFile fontFile(CDirectoryUtils::stylesheetsDirectory() + "/" + fileNameFontsModified());
+        const QString qssWidget(u"QWidget {\n" % qss % u"}\n");
+        const QString fn = CFileUtils::appendFilePaths(CDirectoryUtils::stylesheetsDirectory(), fileNameFontsModified());
+        QFile fontFile(fn);
         bool ok = fontFile.open(QFile::Text | QFile::WriteOnly);
         if (ok)
         {
@@ -260,6 +265,10 @@ namespace BlackGui
             fontFile.close();
             ok = this->read();
         }
+        else
+        {
+            CLogMessage(getLogCategories()).warning(u"Cannot open file '%1' for writing") << fn;
+        }
         return ok;
     }
 

src/blackgui/stylesheetutility.h

@@ -12,6 +12,7 @@
 #define BLACKGUI_STYLESHEETUTILITY_H
 
 #include "blackgui/blackguiexport.h"
+#include "blackmisc/logcategorylist.h"
 #include "blackmisc/restricted.h"
 #include "blackmisc/digestsignal.h"
 
@@ -40,6 +41,9 @@ namespace BlackGui
         //! Constructor
         explicit CStyleSheetUtility(BlackMisc::Restricted<CGuiApplication>, QObject *parent = nullptr);
 
+        //! Log cats.
+        static const BlackMisc::CLogCategoryList &getLogCategories();
+
         //! Style for given file name
         QString style(const QString &fileName) const;